Flat multiconductor cable and process for manufacture thereof

Abstract

Lamination of thermoplastic fluorocarbon resins with unsintered, extruded PTFE is accomplished in order to insulate products, such as conductors in the manufacture of multiconductor cable, by drawing the unsintered PTFE containing the product embedded in it pressed against the thermoplastic fluorocarbon resin through a sintering zone to melt the thermoplastic resin and snter the PTFE, thereby laminating the two together. In the preferred arrangement a second PTFE tape, which can be sintered or unsintered tape, is also laminated at the same time to the thermoplastic resin, such that the final product essentially presents PTFE outer surfaces with thermoplastic fluorocarbon resin bonding the layers of PTFE.

I claim: 
     
       1. A process for producing flat multiconductor cable which comprises drawing a first sheet of unsintered, extruded PTFE having a plurality of parallel conductors embedded lengthwise in one surface thereof together with a second sheet of thermoplastic fluorocarbon resin and a third sheet of sintered PTFE disposed on the opposite side of said second sheet of thermoplastic fluorocarbon resin from said first sheet of unsintered, extruded PTFE lengthwise through a sintering zone for a sufficient period of time and at a sufficient temperature to sinter said extruded PTFE and to melt said thermoplastic fluorocarbon resin while pressing said extruded PTFE sheet against said fluorocarbon resin and said sintered PTFE with said conductors between said first and second sheets whereby upon removal of the assembly from said sintering zone and then cooling, said three sheets are laminated together. 
     
     
       2. A process according to claim 1 in which said thermoplastic fluorocarbon is the copolymer of tetrafluoroethylene and hexafluoropropylene (FEP). 
     
     
       3. A process according to claim 1 in which a pair of metal wires of a metal having a low thermal coefficient of expansion are embedded in said unsintered, extruded PTFE sheet on the side thereof opposite said conductors, one of said wires being located in each marginal portion of said sheet. 
     
     
       4. A process according to claim 3 in which the marginal portions of the laminated assembly withdrawn from said sintering zone are trimmed against said metal wires as guides. 
     
     
       5. The product of the process of claim 1. 
     
     
       6. The product of the process of claim 2.